Authentic science education has received increased attention in recent years, but it remains unclear what constitutes authenticity. Here, we use notions from the Anthropological Theory of the Didactic to approach authenticity. We take a point of departure in an existing education programme in a museum, and analyse it to pinpoint what constitutes its authenticity. We then use the theory of didactical situations as a way to construct a reference model; this reference model constitutes an authenticity-optimised version of the programme. We conclude by briefly discussing the implications of our findings.